Random stuttering or freezing might have to do with older/weaker CPUs not being able to properly deal with ESO's multithreading code.
You can try disabling it. Try downloading my addon ESO Toolbox (from curse.com or esoui.com).
Once installed, go into the game, hit Escape and open the Options menu. There should be a new entry Addon Settings (you might have had it before), which has a sub menu ESO Toolbox.
You might have to scroll down a bit, find the multithreading option and switch it, then restart the game client and see whether your problems persist. If they're gone. Keep the setting. If the issues persist, revert the change (since the game should run more performant on modern PCs while it's enabled).
As a second approach, try disabling Vertical Synchronization in the Video settings.
We have a few steps from our knowledge base that tend to help with short stutters,
Closing the Launcher while playing. This has helped in some cases.
Making sure your graphics drivers are up to date.
Running in a non-windowed fullscreen mode.
Disable or uninstall any add-ons.
Delete you usersettings.txt file in Documents\Elder Scrolls Online\Live or Liveeu
Check the "usersettings.txt"' file: Access the folder for The Elder Scrolls Online on your Documents (by default it should be C:\Documents and Settings\<user name>\My Documents\Elder Scrolls Online\Live) and open the file "usersettings.txt" with the notepad (or your word editor of choice).◦Once open find the lines stating "RequestedNumJobThreads" and "RequestedNumWorkerThreads" (you can do this by pressing the keys "Ctrl" and "F")
◦Change them as below.
SETRequestedNumJobThreads "-1"
SETRequestedNumWorkerThreads "-1"
To:
SETRequestedNumJobThreads "-1"
SETRequestedNumWorkerThreads "0"